diff --git a/var/spack/repos/builtin/packages/openpmd-api/package.py b/var/spack/repos/builtin/packages/openpmd-api/package.py
index a14d78d9de2884d8d24737d2c6d5012a78fade6c..c7e05916854614135d273e036a762fea1513d2d7 100644
--- a/var/spack/repos/builtin/packages/openpmd-api/package.py
+++ b/var/spack/repos/builtin/packages/openpmd-api/package.py
@@ -24,27 +24,29 @@ class OpenpmdApi(CMakePackage):
             description='Enable ADIOS1 support')
     variant('adios2', default=False,
             description='Enable ADIOS2 support')
-    # variant('json', default=True,
-    #         description='Enable JSON support')
-    variant('python', default=True,
+    variant('json', default=True,
+            description='Enable JSON support')
+    variant('python', default=False,
             description='Enable Python bindings')
 
-    depends_on('cmake@3.10.0:', type='build')
+    depends_on('cmake@3.11.0:', type='build')
     depends_on('mpark-variant@1.3.0:')
     depends_on('catch@2.3.0: ~single_header', type='test')
     depends_on('mpi@2.3:', when='+mpi')  # might become MPI 3.0+
     depends_on('hdf5@1.8.13:', when='+hdf5')
     depends_on('hdf5@1.8.13: ~mpi', when='~mpi +hdf5')
     depends_on('hdf5@1.8.13: +mpi', when='+mpi +hdf5')
-    depends_on('adios@1.10.0:', when='+adios1')
-    depends_on('adios@1.10.0: ~mpi', when='~mpi +adios1')
-    depends_on('adios@1.10.0: +mpi', when='+mpi +adios1')
-    depends_on('adios2@2.1.0:', when='+adios2')
-    depends_on('adios2@2.1.0: ~mpi', when='~mpi +adios2')
-    depends_on('adios2@2.1.0: +mpi', when='+mpi +adios2')
+    depends_on('adios@1.13.1:', when='+adios1')
+    depends_on('adios@1.13.1: ~mpi', when='~mpi +adios1')
+    depends_on('adios@1.13.1: +mpi', when='+mpi +adios1')
+    depends_on('adios2@2.3.0:', when='+adios2')
+    depends_on('adios2@2.3.0: ~mpi', when='~mpi +adios2')
+    depends_on('adios2@2.3.0: +mpi', when='+mpi +adios2')
+    depends_on('nlohmann-json@3.4.0:', when='+json')
     # ideally we want 2.3.0+ for full C++11 CT function signature support
-    depends_on('py-pybind11@2.2.3:', when='+python')
+    depends_on('py-pybind11@2.2.3:', when='+python', type='link')
     depends_on('py-numpy@1.15.1:', when='+python', type=['test', 'run'])
+    depends_on('python@3.5:', when='+python', type=['link', 'test', 'run'])
 
     extends('python', when='+python')
 
@@ -61,8 +63,8 @@ def cmake_args(self):
                 'ON' if '+adios1' in spec else 'OFF'),
             '-DopenPMD_USE_ADIOS2:BOOL={0}'.format(
                 'ON' if '+adios2' in spec else 'OFF'),
-            # '-DopenPMD_USE_JSON:BOOL={0}'.format(
-            #     'ON' if '+json' in spec else 'OFF'),
+            '-DopenPMD_USE_JSON:BOOL={0}'.format(
+                'ON' if '+json' in spec else 'OFF'),
             '-DopenPMD_USE_PYTHON:BOOL={0}'.format(
                 'ON' if '+python' in spec else 'OFF'),
             # tests and examples
@@ -72,12 +74,15 @@ def cmake_args(self):
                 'ON' if self.run_tests else 'OFF'),
         ]
 
+        # switch internally shipped third-party libraries for spack
         if spec.satisfies('+python'):
             args.append('-DopenPMD_USE_INTERNAL_PYBIND11:BOOL=OFF')
             args.append('-DPYTHON_EXECUTABLE:FILEPATH={0}'.format(
                         self.spec['python'].command.path))
 
-        # switch internally shipped third-party libraries for spack
+        if spec.satisfies('+json'):
+            args.append('-DopenPMD_USE_INTERNAL_JSON:BOOL=OFF')
+
         args.append('-DopenPMD_USE_INTERNAL_VARIANT:BOOL=OFF')
         if self.run_tests:
             args.append('-DopenPMD_USE_INTERNAL_CATCH:BOOL=OFF')